All references are available in the References tab. Existing drug reduces symptoms by 45 percent. This buildup makes it harder for sperm to enter the cervix. Pills increase breast size not as often as weight gain, some girls also report an increase in cup size once starting the Pill. Log in with your Medical News Today account to create or edit your custom homepage, catch-up on your opinions notifications and set your newsletter preferences. Like the possible increase in breast size, any associated weight gain is typically slight.